The present invention relates to an antidiabetic, particularly to a preparation for directly controlling, namely decreasing both a post prandial blood glucose level and a fasting blood glucose level of diabetic patients with one preparation to make these levels close to normal levels.
Ordinary antidiabetics are antidiabetics for decreasing either a post prandial blood glucose level or a fasting blood glucose level to make it close to a normal level. As antidiabetics for decreasing a post prandial blood glucose level to make it close to a normal level, nateglinide has been developed, and it is described in, for example, Japanese Patent Publication No. 15,221/1992 or Japanese Patent Laid-Open No. 194,969/1998. Further, antidiabetics for decreasing a fasting blood glucose level to make it close to a normal level are described in, for example, Kondo Nobuo, Nippon Rinsho, vol. 55, 1997, extra ed., p. 159 and the like. In recent years, for treating diabetes, it has been considered important that both a post prandial blood glucose level and a fasting blood glucose level are decreased to make them close to normal levels.
However, there have been no preparations for decreasing both levels to make them close to normal levels.
The invention is to provide a preparation for directly decreasing both a post prandial blood glucose level and a fasting blood glucose level by one preparation to make them close to normal levels.
The present inventors have assiduously conducted investigations to solve the foregoing problems, and have consequently found that both a post prandial blood glucose level and a fasting blood glucose level can be decreased by one preparation to make them close to normal levels. This finding has led to the completion of the invention.
That is, the invention provides an antidiabetic preparation for oral administration characterized by containing active ingredient (s) for decreasing blood glucose level of diabetic patients and having a form to make both a post prandial blood glucose level and a fasting blood glucose level of diabetic patients close to normal levels.
The invention further provides an antidiabetic preparation for oral administration characterized by containing nateglinide in which in a dissolution test for 1 hour, a dissolution rate of the active ingredient is at least 1% and less than 70% at pH of 1.2, 4.0 and 6.8.
The invention still further provides an antidiabetic preparation for oral administration containing nateglinide in which a dissolution rate of nateglinide is dependent on pH and in a dissolution test for 1 hour, a dissolution rate of nateglinide at pH of 1.2 is at least 20% lower than a dissolution rate thereof at pH of 6.8.
The invention furthermore provides an antidiabetic preparation for oral administration containing nateglinide in which in a dissolution test for 1 hour, a dissolution rate of the active ingredient at pH of 4.0 is less than 20% and a dissolution rate of the active ingredient at pH of 6.0 is at least 20%.
The invention moreover provides an antidiabetic preparation for oral administration containing nateglinide and at least one material selected from the group consisting of polysaccharide derivatives, polyacrylic acid derivatives, polylactic acid derivatives, polyoxyethylene derivatives, polyvinyl pyrrolidone derivatives, polyvinyl alcohol derivatives, oils and surfactants, nateglinide being dispersed in the material or being emulsified or microencapsulated with the material.
The invention moreover provides an antidiabetic preparation for oral administration containing nateglinide and at least one material selected from the group consisting of polysaccharide derivatives (except for hydroxypropylmethyl cellulose), polyacrylic acid derivatives, polylactic acid derivatives, polyvinyl pyrrolidone derivatives, polyvinyl alcohol derivatives, oils and surfactants, nateglinide being coated with the material.